20. Where a Government security stands in the name of or is held by a minor or a person who is insane and incapable of managing his affairs, the interest accruing thereon, or the capital sum payable in respect thereof on the maturity or discharge of the loan, shall, where, in the case of interest payable, the nominal value of the security, or in other cases the sum payable, does not exceed five thousand ¹[Taka], be paid in such manner as may be prescribed, and on any payment being so made, the Government shall, notwithstanding any provision of any enactment to the contrary, be discharged from all liability in respect thereof.